A conventional four-rotor aircraft, six-rotor aircraft or eight-rotor aircraft can merely perform some simple flight actions due to limitations of aerodynamic structures. Multiple additional mechanical structures need to be added when difficult flight actions (such as roll and “swing” action of the aircraft body) need to be performed, which results in particularly complicated mechanical structures of the aircraft.
For example, four propellers are used to provide a lifting force in the four-rotor aircraft. In such a case, real-time computation is made based on data from sensors in the aircraft body, then an aircraft attitude (i.e., a roll angle of the aircraft relative to a horizontal plane) is estimated by using an inertial navigation algorithm, and speeds of four motors for providing the lifting force are respectively adjusted according to a current roll angle of the aircraft body. Propellers have to output a thrust force in a direction opposed to an original direction, when the aircraft need to fly with a roll angle of 180°. In known technical solutions, generally, propellers are separated into two parts which are able to move independent of each other, and the direction of the thrust force output from the propellers can be directly changed by changing pitches of propellers via a steering engine and a number of transmission mechanisms. The existing solutions need additional complex transmission mechanisms, thereby increasing the complexity of the structure of the aircraft. Furthermore, transmission mechanism needs to be manually debugged during production, and even a slight impact may affect the stability of the complex transmission mechanisms in use.